Method for providing mounting brackets on a cathode ray tube integral with the implosion protection system of the cathode ray tube

ABSTRACT

A method of providing mounting brackets on a cathode ray tube which utilizes an implosion protection system of the type comprising a rimband member positioned near the mold match line of the panel portion of the cathode ray tube. The rimband consists of two symmetrical half sections which are secured to the rear of the viewing area of the cathode ray tube by means of a tension band. The mounting lugs are provided on the rimband and are accurately positioned with respect to predetermined points located on the diagonals of the face plate of the cathode ray tube and referred to as the Z-points in the industry to insure that when the cathode ray tube is mounted within a cabinet or chassis that the cathode ray tube face plate will be accurately positioned with respect to a portion of the cabinet normally the bezel.

United States Patent McLeod et al.

[45) July 11, 1972 [54] METHOD FOR PROVIDING MOUNTING BRACKETS ON A CATHODE RAY TUBE INTEGRAL WITH THE IMPLOSION PROTECTION SYSTEM OF THE CATHODE RAY TUBE [72] Inventors: Garth M. McLeod, Dundee; Cflnton R.

Copeland; Gilbert N. g both of Elmira, all of NY.

[73] Assignee: Westinghouse Electric Corporation, Pittsburgh, Pa.

[22] Filed: Oct. ll, I927 [2]] Appl. No.: 80,080

[5 6] References Cited UNITED STATES PATENTS Albrecht ..29/25.l X

2,809,279 lO/I957 Minneman et a]. .29/25. II Bongenaar et al. ..29/2S. l 3

I ABSTRACT A method of providing mounting brackets on a cathode ray tube which utilizes an implosion protection system of the type comprising a rimband member positioned near the mold match line of the panel portion of the cathode ray tube. The rimband consists of two symmetrical half sections which are secured to the rear of the viewing area of the cathode ray tube by means of a tension band. The mounting lugs are provided on the rimband and are accurately positioned with respect to predetermined points located on the diagonals of the face plate of the cathode ray tube and referred to as the Z-p0ints in the industry to insure that when the cathode ray tube is mounted within a cabinet or chassis that the cathode ray tube face plate will be accurately positioned with respect to a p0rtion of the cabinet normally the bezel 2 Claims, 3 Drawing gum PATENTEDJUL 1 1 I972 SHEET 1 OF 2 INVENTORS Garth M McLeod,CliMon R. Copeland METHOD FOR PROVIDING MOUNTING BRACKETS ON A CATIIODE RAY TUBE INTEGRAL WITH THE IMPLOSION PROTECTION SYSTEM OF THE CATHODE RAY TUBE BACKGROUND OF THE INVENTION This invention relates to methods of securing banded type integral implosion systems to cathode ray tubes which also include mounting brackets that are accurately positioned so as to insure proper mounting within the cabinet or housing. Implosion protection systems of the banded type are well known in the art as exemplified in structures such as set forth in US. Pat. No. 3,220,592 issued D. E. Powell et al. In addition, US. Pat. No. 3,510,589 issued to P. Schmidt and US. Pat. No. 3,5l2,234 issued to H. Bongenaar et al. illustrate integral implosion systems of the banded type for cathode ray tubes and incorporating integral mounting lugs for mounting the cathode ray tube within a housing or cabinet.

The normal procedure in assembling these implosion systems is to provide an adhesive material on the inner surface of a rimband member. The rimband member may be in the form of two half sections and these two sections are positioned about a portion of the cathode ray tube near or on the mold match line and to the rear of the front face or the viewing portion of the tube. The mounting lugs may be provided on this rimband member and secured thereby by welding or other means. A tension band is provided about the rimband member and is placed under tension and in this manner secures the rimband securely to the cathode ray tube.

The present systems rely on the rimband fitting the glass contour of the envelope so as to accurately position the mounting brackets or lugs with respect to a predetermined point on the diagonal and near the corner of the face plate of the cathode ray tube. This predetermined point is normally referred to as the 2-point in the industry and is located on the outside surface of the face plate. The Z-point is located on the screen diagonal at a point 0. I25 inch beyond the minimum screen. This point is used as a reference by receiver manufacturers in specifying the position that the mounting lug should be on the cathode envelope. [t has been found that the glass contour of the envelopes may vary between manufacturers and even within the production of one manufacturer. Another problem associated with this mounting arrangement is that the rimband members may be out of tolerance and this combination of effects may result in the mounting lugs being improperly positioned. When the cathode ray tube is then mounted in the receiver, the result is that the longitudinal axis of the cathode ray tube may not be normal to the front surface of the receiver if the receiver includes a bezel then there may be a gap between the bezel and the cathode ray tube or there may be such pressure on the bezel as to cause damage to the bezel or tube.

It is accordingly in this background that this invention was made in order to insure accurate positioning of the mounting brackets with respect to the Z-points on the cathode ray tube. This means that the mounting brackets must be accurately positioned in a plane normal to the axis of the cathode ray tube and positioned at a fixed distance with respect to a plane normal to the axis of the tube and passing through the 2- points. In addition, the mounting brackets must be mounted accurately about the perimeter of the cathode ray tube to insure that the openings in the mounting brackets will be accurately located with respect to the mounting bolts in the receiver and to insure that the long axis of the face plate of the cathode ray tube is in a horizontal plane.

SUMMARY OF THE INVENTION This invention is directed to the method of and apparatus for securing a banded implosion protection system to a cathode ray tube including mounting brackets integral with the implosion protection system in which the mounting brackets are accurately positioned with respect to the Z-points or other coplanar points on the cathode ray tube face. More particularly, the invention is directed to the method of supporting the cathode ray tube by support means located at the Z-points of the face plate and with fixtures accurately positioned with respect to said support means to provide a holding surface for the mounting brackets so that the mounting brackets are accurately positioned with respect to the support means located at the 2-point.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, reference may be had to the preferred embodiment, exemplary of the invention, shown and illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of a television receiver partially cut away illustrating the mounting arrangement of a cathode ray tube within a cabinet;

FIG. 2 is a top view of a banding fixture for a cathode ray tube with a cathode ray tube mounted therein and illustrating of the teachings of this invention; and

FIG. 3 is a sectional view taken along line Ill-III of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring in detail to FIG. 1, there is illustrated a portion of a television cabinet 12 with a cathode ray tube 14 mounted therein. Only one of the mounting corners of the cathode ray tube 14 is illustrated. A rimband 16 is positioned about the cathode ray tube and to the rear of the viewing area 18 of the face plate 19 the cathode ray tube 14. A mounting bracket 20 is secured to the rimband 16 as illustrated and a bolt 22 passing through a hole 21 in the bracket 20 secures the mounting bracket 20 to the cabinet 12. The cabinet 12 includes a rectangular bezel 24 which masks off the non-viewing portion of the face plate 19. A tension band 26 secures the rimband 16 to the cathode ray tube 14.

A Z-point 28 is illustrated on the tube face 18 and a bezel 24 normally comes to approximately that point. The Z-points 28 which lie on the diagonals of the cathode ray tube 14 at the four corners of the rectangular tube are in a common plane normal to the longitudinal axis of the tube 14. The mounting brackets 20 which also are located at the four comers of the cathode ray tube 14 lie in a common plane normal to the longitudinal axis of the cathode ray tube 14 and parallel to the common plane of the Z-points. These two planes are spaced at a distance of about A to Hi inches as illustrated in FIG. I. This distance is sometimes referred to as the Z-distance. This Z-distance is normally specified by the receiver manufacturer and is the critical spacing of the mounting lugs with regard to the viewing face plate. The spacing of the holes 21 provided in the brackets 20 is normally specified by the receiver manufacturer and usually the four holes in the bracket 20 have their centers on the corner of a rectangle having a center common with the center of the face plate 19 of the cathode ray tube 14.

FIGS. 2 and 3 illustrate a banding apparatus for practicing the teachings of this invention. The banding apparatus includes a table 40 having a centrally located vacuum chuck 42 which engages the face plate 19 of the cathode ray tube 14. Four corner support assemblies 50, 52, 54 and 56 are positioned on the table 40. Each of the four comer support assemblies 50, 52, 54 and 56 includes Z support members 44 which are secured to the table 40 and are adjustable in height and supports the cathode ray tube 14 at the Z-points. The corner support assemblies 50, 52, 54 and 56 include a block member 58 which is secured to the table 40 and extends above the Z- supports 44. The block member 58 is positioned at a greater radial distance from the center of the rectangular type support structure than the Z-support 44. A surface 60 of the block 58 facing the center of the rectangle provides a surface that radially orients the tube face 18 in a plane perpendicular to the tube axis. A further recessed surface 62 is also provided above the surface 60 to permit insertion of the tension band 26. The block portions 58 also have an upper surface 64 on which the mounting bracket 20 rests. The support assemblies 52 and 56 also have a guide member 66 provided on the surface 64 to accurately position the brackets 20 with respect to the perimeter of the cathode ray tube 14. The rimband member 16 normally consists of two half sections so that in this manner a guide 66 is provided for one bracket on each of the half sections.

Clamping members 70 are provided in combination with the comer support blocks 50, 52, 54 and 56. These clamping members 70 hold the bracket members 20 down against the surfaces 64 of the comer supports 50, 52, 54 and 56.

In the assembly operation, the cathode ray tube is placed in the comer supports 50, 52, 54 and 56 and rests on the 2-point supports 44. The rimband 16 which may be in the form of two half sections is coated with a suitable adhesive such as an epoxy resin and is inserted around the cathode ray tube 14 as indicated. The vacuum chuck 42 may be activated at this time to pull the cathode ray tube 14 down firmly against the 2- points l4 and also seat the cathode ray within the rim-band R6. The locking members 70 are secured over the brackets 20 so as to press them against the surface 64 prior to pulling the cathode ray tube down by the vacuum chuck. The tension band 26 is then inserted about the cathode ray tube 14 as indicated and is pulled tight and secured by a suitable mechanical fastening means so as to provide a residual pressure. The vacuum is then released and the tube is removed.

By this procedure a plane passing through the Z-points on the cathode ray tube 14 is parallel to a common plane which passes through the surfaces 64 and supports and places the brackets 20 in a common plane parallel to the common plane passing through the 2. points. This accurately dimensions the distance between the brackets 20 and the Z-points while the guides 66 accurately position the brackets 20 with regard to the perimeter of the cathode ray tube 14. The guides 66 are set up to insure that the openings in the brackets 20 form a rectangular configuration with the center of the rectangular coinciding with the center of the cathode ray tube viewing screen.

it is obvious that the invention is susceptible of various changes and modifications without departing from the spirit thereof.

We claim as our invention:

1. Die method of providing mounting brackets about a rectangular cathode ray tube for supporting said cathode ray tube in a television set comprising the steps of supporting said cathode ray tube at four predetermined reference points located on the diagonals and near the comers of the outer surface of the face plate of said cathode ray tube so that said four supporting points on said cathode ray tube lie within a first plane, positioning a rimband about said cathode ray tube with mounting brackets provided thereon and near the corners of said face plate, positioning said mounting brackets on support surfaces lying in a second plane and parallel to said first plane, securing said mounting brackets to said surfaces and applying a tension band about said rimband to securely fix said rimband to said cathode ray tube and position said mounting brackets within a third plane parallel to said first plane.

2. The method set forth in claim 1 which further includes the step of positioning at least one of said mounting brackets peripherally with respect to said cathode ray tube so as to provide a rectangular configuration of four mounting brackets with the openings therein lying substantially on the comers of a rectangular with the center of said rectangular lying substantially at the center of said face plate of said cathode ray tube. 

1. The method of providing mounting brackets about a rectangular cathode ray tube for supporting said cathode ray tube in a television set comprising the steps of supporting said cathode ray tube at four predetermined reference points located on the diagonals and near the corners of the outer surface of the face plate of said cathode ray tube so that said four supporting points on said cathode ray tube lie within a first plane, positioning a rimband about said cathode ray tube with mounting brackets provided thereon and near the corners of said face plate, positioning said mounting brackets on support surfaces lying in a second plane and parallel to said first plane, securing said mounting brackets to said surfaces and applying a tension band about said rimband to securely fix said rimband to said cathode ray tube and position said mounting brackets within a third plane parallel to said first plane.
 2. The method set forth in claim 1 which further includes the step of positioning at least one of said mounting brackets peripherally with respect to said cathode ray tube so as to provide a rectangular configuration of four mounting brackets with the openings therein lying substantially on the corners of a rectangular with the center of said rectangular lying substantially at the center of said face plate of said cathode ray tube. 